Geographical Profiling

Geographical profiling enables you to find vehicles captured by an Automatic License Plate Recognition (ALPR) system, that were detected in the vicinity of an event. This gives you the opportunity to carry out searches for vehicles, captured by a camera, traveling in the area, around a specified date and time.

You can compare vehicles recorded near a series of events to establish if any of these vehicles are common to more than one of the events.

The process of geographical profiling comprises the following steps:

Select the events to be analyzed
Specify the dates and times of interest
Specify the geographical area of interest
Examine the number of Plate Analysis reads that are found
Analyze the vehicles that are associated with two or more events

There are a number of ways that the results of the analysis can be stored for further examination.

Geographical profiling has multiple screens, click Next or Back to move between them.

Select Events

The source for geographical profiling is one or more events; for example a series of related crimes or incidents. The source records must be event entities as specified in the Plate Analysis configuration. You can specify the source records in one of three ways:

specify a query that returns event records in the results
specify a set that contains event entities
specify event entities individually

In each case, all the event entities must include valid location information in the form of coordinate data.

Specify Dates and Times

When you have selected the events of interest, you need to set the dates and times, relative to the date and time of each incident, that you want to examine. You do this by specifying offsets from the date and time of the event. This can be done individually for each event, or can be set for all events that you select. In this way for example, you can specify that you want to analyze all ALPR reads that were recorded up to one hour before an event and up to five hours after. Alternately you can specify the time before and after individual events down to the nearest minute.

Note: If one of the dates for an event is blank then Plate Analysis will use the same already populated value for both start and finish dates. If both dates are blank then both fields will be left blank, and the results will be sorted at the top of the display.

When offsets have been set for each event, you can adjust the offsets, individually or collectively, for even finer control of your analysis. For example if you have set up different offsets for each event, you can select them all and add an extra ten minutes to the time after the event.

Offsets can be specified in days, hours and minutes, and can be positive or negative. The specified offset is displayed in the list of events.

Setting Geographical Area

The location of the Plate Analysis reads to be analyzed can be either relative to the locations of the events, or can be defined as a specific area.

You can set a geographical tolerance around the coordinates in terms of the distance North, South, East, and West of each event. As before, you can do this for each record individually, or select more than one event and set the tolerance for all the selected items.

If appropriate you can specify any camera location for one or more events by choosing a location inside a rectangle defined by specified pairs of coordinates.

Note: If any of the specified events do not have coordinate data, you see a message telling you how many of the records do not have coordinates. These events are not analyzed.

Examine Number of ALPR Reads

The first result you see is a list of events with the number of associated ALPR reads that have been detected within your specified date, time, and area. At this stage you can examine the Plate Analysis records for each event or add them to a new or existing set for further analysis.

Analyze Vehicles Associated With Events

The final result of Geographical Profiling is a list of Vehicle Registration Marks (VRMs) that are associated with two or more events. By selecting each VRM in turn, you can see which events are associated with each one. You can select one or more of the VRMs and copy the list to the clipboard or into a text file; the list can then be used for further analysis, for example as input to an iBase query using an in list parameter.